Operating frequency. JB's post.

[tabdog]

JB posted this on tha Metal Detectin section of tha Finds Forum.

I thought it was informative.

For those who missed it here it is.

[size=medium]George Payne designed the first detectors with ground balance capability, discrimination, ID meters, tone ID and almost all of the other features on modern detectors. Even David Johnson, who is undoubtly a genius when designing detectors is concerned, who designed many of the current detectors including the new Fisher series, several Whites and Tesoro models and and the Shadow X5 says George Payne is still the master. Below is an excerpt from one of the articles on my website George wrote, followed by an article by Gary Finch.[/size]

[size=medium]The target signal returned to the receive coil can be thought of as composed of two components, one we call x and one we call r. The polarity of the x signal (its direction) tells us if the target is ferrous or non-ferrous. The r signal has only one polarity. Also, the ratio of the x and r signal tells us the target

 

[slingshot]

Thanks for that post---very encouraging. Also, the best operating frequency, IMHO, is at least 3 times a day, at 2 hours a pop!

 

[Gunnar of bradford MN]

n/t

 

[jamt225]

where does the Tejon's 17 -18 khz fit in this picture?

 

[trueblue]

where does the Tejon's 17 -18 khz fit in this picture?

dont forget the Lobo

 

[dahut]

Just a little higher than the 12.5khz Payne says is optimum. This means that it responds to lower conductivity targets a bit better than others.

As right as Mr. Payne was about that 10-15khz range, there is no single best frequency. These discussions always leave someone coming away with that idea.
Much can be done in both circuitry and software (where applicable) to adapt a given frequency to our purpose.

 

[tabdog]

Several machines have been developed that
utilize frequencies higher than 15kHz. Many
are multi-frequency machines. Some like tha
Tejon and tha Garrett Scorpion Gold Stinger,
are are single frequency.

I do not understand tha topic well enough to
discuss the advantages and disadvantages of
these machines, or their operating frequencies.

I've used more industrial metal detectors than
hobby detectors. I surveyed for over 30 years,
searchin for property corners and utilities.

I have used sound to detect with for over 30
years. But I have never used a 4 filter machine
or any of tha multi filter machines.

Tha Cibola and V are tha highest operating
frequency I have used in a 2 filter VLF detector.

I tried some mid-range TID machines, but did
not like them.

I'm stuck on tha 2 pound, analog machines.

I'm just learnin this stuff.

HH,

Tabdog

 

[JB(MS)]

You're right David. There are variables that play a role in determining the best frequency for a given location, and anyone reading this, or previous posts about transmit frequencies, needs to take into consideration that we're splitting hairs here, and in all probability most would never realize much of a difference in average ground conditions. If I wasn't a compulsive tester I probably wouldn't have noticed any difference, but I've spent a lot of time for a lot of years and too much money comparing way too many different detectors - in air tests and on inground targets, for depth, response to targets at different conductivity levels, target separation and see through small iron ability - and as a result settled on the Barons that transmit at 12.5 khz as my main detectors, plus a 1990 model 15 khz Gold Mountain GMT 1650 and a 1974 100 khz Compass TR for hunting in iron and the Golden

 

[jamt225]

minelab's take on the subject:

http://www.minelab.com/consumer/xstandard/files/ML_08_007WhitePaper8.pdf

 

[tabdog]

n/t

 

[dahut]

n/t